Musical instrument employing time division multiplexing techniques to control a second musical instrument

ABSTRACT

A system for controlling the operation of tone producing components of one musical instrument from the keyboard of a manually played musical instrument involves the use of an encoder that produces a series of time multiplexed signals during each time frame or operating cycle for the encoder. These signals are generated in response to the detected play of musical tones on the instrument and are transmitted to a decoder for decoding the signals and controlling the operation of the tone producing components of the controlled instrument. Conditions which develop from the play of each musical tone are monitored and sensed by an electronic sampling technique that stores electronic data indicative of the sampled conditions. This stored data is then screened to detect the tones being played at the time of the sample and an appropriate signal indicating the play of the tone is generated in a specific time slot that has been assigned to the tone. A system is disclosed for use with a manually played guitar which involves processing the data relative to the sensed condition so as to detect those conditions indicative of a tone being played on a guitar string. A system for use with a manually played accordian is also shown and which involves the use of radio transmission and receiving means for transmitting the time multiplexed signals, the embodiment disclosed involving the use of pulse width encoding and decoding means so as to enable transmission of control signals, clock pulses and generated time multiplexed signals in a composite form. A manually controlled system for sustaining the play of tones on the controlled instrument is also disclosed.

United States Patent Bonham Mar. 18, 1975 [76] Inventor: Arthur R. Bonham, 5614 Lejeune Dr., Orlando, Fla. 32808 22 Filed: Dec. 12, 1973 21 Appl.No.:423,93S

[52] US. Cl 84/1.16, 84/1.01, 84/l.03, 84/115, 84/171, 84/D1G. 30 [51] Int. Cl. G10h l/00, GlOh 5/00 [58] Field of Search 84/1.0l, 1.03,1.16,1.17, 84/1.28, 2, 115, 170-172, 263, DIG. 29, DIG. 30

[56] References Cited UNITED STATES PATENTS 3,116,357 12/1963 Krebs 84/l.16 3,388,206 6/1968 Sines 84/l.16 3,482,028 12/1969 Cox et a1. 84/1.16 3,530,226 9/1970 Wheeler et a1. 84/1.16 3,604,299 9/1971 84/1.03 3,610,799 10/1971 84/1.0l 3,647,929 3/1972 84/1.0l 3,683,096 8/1972 Peterson et al 84/115 3,697,661 10/1972 Deutsch 84/l.0l 3,781,452 12/1973 Vauclain 84/l.28 3,789,719 2/1974 Attorney, Agent, or Firm-Roger L. Martin, Esq.

Maillet .11... 84/115 [57 ABSTRACT A system for Controlling the operation of tone producing components of one musical instrument from the keyboard of a manually played musical instrument involves the use of an encoder that produces a series of time multiplexed signals during each time frame or operating cycle for the encoder. These signals are generated in response to the detected play of musical tones on the instrument and are transmitted to a decoder for 'decoding the signals and controlling the operation of the tone producing components of the controlled instrument. Conditions which develop from the.play of each musical tone are monitored and sensed by an electronic sampling technique that stores electronic data indicative of the sampled conditions. This stored data is then screened to detect the tones being played at the time of the sample and an appropriate signal indicating the play of the tone is generated in a specific time slot that has been assigned to the tone. A system is disclosed for use with a manually played guitar which involves processing the data relative to the sensed condition so as to detect those conditions indicative of a tone being played on a guitar string. A system for use with a manually played accordian is also, shown and which involves theme of radio transmission a'nd receiving means for transmitting the time multiplexed signals, the embodiment disclosed involving the use of pulse width encoding and decoding means so as to enable transmission of control signals, clock pulses and generated time multiplexed signals in a composite form. A manually controlled system for sustaining the play of tones on the controlled instrument is also disclosed.

5 Claims, 9 Drawing Figures TIME GENERATOR i rm- V I SLOT 22 STRING 'AND SWITCH CONDITION SAMPLINGAND DATA PROCESSOR 14 1a OSCIL' I f TONE SUSTAIN LATOR CONTROL SECTION E TIME 2355 55; 5 25 uumnmosisum. PROCESSOR i 1 l L J lH-l-H- 2 C. i

6 ORGAN 2 7 'oncm TONE AND AUDIO 53%,? VOICING SWITCHES AMPL'F'ER l MUSICAL INSTRUMENT EMPLOYING TIME DIVISION MULTIPLEXING TECHNIQUES TO CONTROL A SECOND MUSICAL INSTRUMENT BACKGROUND OF THE INVENTION This invention relates to musical instruments, and more particularly to control systems for use in controlling the play of one instrument from the keyboard of another so that both instruments may be played in duet fashion by one person.

Systems for controlling the operation of the tone producing components of one musical instrument in accord with the musical tone selections being played manually on a second musical instrument are known. As the musical instrument that is being played manually is keyed to play a selected tone, a condition of the instrument develops which is characteristic of the playing of the tone and this condition can be sensed by appropriate means which can serve to complete a circuit that enables a tone producing component of the controlled instrument and which serves to produce a tone harmonically related to the tone selection being played on the first instrument. As an example, when the piano key associated with the middle C" tone that is playable on a piano is depressed, this depressed condition can be sensed through the use of an appropriate switch which completes a circuit when the key is depressed. This circuit on being energized can serve to operate a solenoid which in turn actuates and depresses the middle C" piano key of a second piano. As such, both pianos can be played by one person.

The concept of controlling the play of one musical instrument from the keyboard of another musical instrument is fairly well advanced in the art so that technology exists for the playing of pianos and organs, both pipe and electronic, as well as many other instruments from the keyboards of accordians, guitars and other musical instruments that are played manually.

The main problem that exists with the prior art control systems whichare currently in use lies in the large number of electrical conduits or wires that are needed in order to interconnect the condition sensors of the manually played instrument and the tone enabling or actuating circuit components associated with the harmonically related musical tones that are playable on the controlled instrument. For example, the conventional accordian has 41 treble control keys, 12 bass control keys, and 12 chord control keys. If one proposes to control the operation of an electronic organ from the keyboard of the accordian and where the electronic organ has l2 voicing control circuits, the need exists for about 80 wires or electrical conduits in order to interconnect the two instruments so that harmonically related tones may be played on the two instruments in duet fashion. In conventional control systems the wires which interconnect the two musical instruments are usually cabled, and when the played instrument is portable, as for example in the case of an accordian or guitar, the cable hampers the movements of the player during stage-type performances. Additionally, the large number of wires that are used also creates a high probability of malfunctioning circuits, and consequently there is a need today for control systems which eliminate or at least minimize the number of wires which interconnect the two musical instruments.

STATEMENT OF THE INVENTION 0 time frame for the encoder. Each tone that is playable on the instrument is assigned to a specific time slot in the operating time frame and when the sensed conditions indicate that the tone is being played a signal is generated during the time slot and transmitted to a decoder that is associated with the controlled musical in- I strument. The decoder is synchronized with the operation of the encoder and decodes the time multiplexed signals and enables the tones producing circuit of the controlled instrument so that the latter is controlled to play tones that are harmonically related to those being played manually by the player of the first instrument. Through the use of the encoding and decoding components of the control system the intelligence embodied in the time multiplexed signals can be transmitted by a single wire or conduit to the decoder or alternatively through the use of appropriately located radio signal transmission and receiving components can be transmitted between the two instruments as a component of a radio signal. The encoder and decoder of the control system are synchronized in their operation by appropriate control signals that are produced by a signal generator that in turn operates in dependency upon receipt of time spaced pulse signals such as produced by an oscillator or other appropriate means. These synchronizing control signals as wellv as the pulse signals may be transmitted between the encoding and decoding components of the control system by means of electrically conductive wires on the other hand, they may be transmitted through the use of radio signals, and together with the time multiplexed signals generated by the encoder may be formed into a composite signal by an appropriate pulse width encoder and transmitted together as a composite signal over a wire or by radio signal transmission means. This composite signal can then be decoded into its respective components which are then used for their intended purposes as will be subsequently seen.

Certain aspects of the invention have to do with a system for controlling the play of a musical instrument from the keyboard of a guitar or other stringed instrument. The control of an electronic organ from the keyboard of a guitar has been accomplished in the past by means described in various patents including Borell U.S. Pat. No. 3,465,086 and more recently in the Borell and Bonham application bearing Ser. No. 280,50l and which was filed Aug. 14, 1972 and is now U.S. Pat. No. 3,786,167. Each of the disclosures referred to show control systems in which the keyed string tones that are playable on the guitar strings are sensed on the basis of string contact with the fret involved in keying the string to play the selected keyed string tone. in the former patent, the string contaet with the fret used in keying the string is used as a basis for controlling the tone producers of the electronic organ to play the organ tone harmonically related to the keyed string tone. The arrangement shown in the latter patent on the other hand relies on string contact when not only the fret against which the string is keyed but also with an adjacent fret in order to enable the appropriate tone producing component of the electronic organ. Certain aspects of the invention relate to controlling the audible tone production of an electronic organ from the keyboard of a guitar and wherein string contact with adjacent frets is detected in the circuits of the encoder and used as a basis for determing the play of the tone and for controlling the tone producers of the electronic organ as will become more apparent with the detailed description which follows.

Yet other aspects of the invention relate to a special effects circuit that permits the performing player of the guitar to initiate the play of a tone or chord on the organ from the keyboard of the guitar or other played instrument and to thereafter sustain the tone or chord playing condition after the harmonically related tones are no longer being played on the manually played instrument.

The novel features which are believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention, itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings, and in which:

FIG. 1 schematically illustrates a system embodying the concepts of the invention for controlling the operation of the tones producing means of an electronic organ in accord with the musical tone selections being played on the guitar;

FIG. 2 schematically depicts in greater detail circuit components of the time slot generator and time slot counter illustrated in FIG. 1 along with circuit components associated with the oscillator component shown therein;

FIG. Ssch'ematically depicts in greater detail the encoder string and switch condition processing section of the encoder shown in FIG. 1 and as seen in reference to the six strings of the guitar and the switches mounted on the guitar for controlling two of ,the voicing circuits of the organ section; I

FIG. 4 schematically depicts in greater detail the components of the serial data signal processor section of the decoder shown in FIG. 1 and as seen in reference to a gate that is utilized in conjunction with the tone sustain control section of the control system shown in FIG. 1;

FIG. 5 schematically depicts in greater detail the components of the tone sustain control section shown in FIG. 1;

FIG. 6 is a timing diagram illustrating the operation of the data processor section of the encoder shown in FIG. 1;

FIG. 7 is a timing diagram illustrating the operation of the data signal processor section of the decoder shown in FIG. 1;

FIG. 8 is a timing diagram which shows the operation of the tone or chord sustain control section shown in FIG. 1; and

FIG. 9 schematically illustrates a system for controlling an electronic organ from the keyboard of an accordian and wherein the signals are transmitted between the component of the control system which are associated with the organ and accordian respectively through the use of radio transmission and receiving means.

The embodiment of the invention which is generally mentioned patents for the general arrangement of the bifurcated fret sections.

The system 10 for controlling the operation of the electronic organ in accord with the musical ton'e selection being played on the guitar includes an encoder 11 which has a time slot generator 12 and a string and switch condition sampling and data processor 13. The guitar is equipped with a plurality of sensors 13a. Part of these sensors 13a are arranged to sense predetermined conditions that develop during the play of the musical tones on the guitar. Others serve to sense the closed status of certain voicing control switches. Processor 13 provides a means for sampling the sensed statuses of those predetermined conditions which develop during the play of the musical-tones on the guitar to detect those tones actually being played and for generating an appropriate signal during the occurrence of those time slots to which the tones being played have been assigned. The various voicing control switches are also assigned to specific time slots in the operating time frames and processor'13 performs a similar sampling and signal general function with respect to the voicing control switches. The generator 12 and processor 13 are preferably suitably mounted in the body of the guitar.

System 10 also includes an oscillator 14 which in the illustrated embodiment is preferably mounted in the area of the electronic organ along with a time slot counter 15 and a time multiplexed signal processor 16 of the decoder component 17 of the system. As an optional feature, the depicted system has a chord or tone sustain section 18 and a gating circuit 19 which, as will be subsequently seen, may be used to sustain operation of organ tone producers that have been enabled by the detected play of a musical tone selection on the guitar for a controllable period which outlasts the play of the musical tone selection on the guitar.

'System 10 is based upon the transmission of a series of time multiplexed signals during each cycle or operating time frame of the encoder and upon the transmission of the cyclic output 20 of the encoder 11 to the time'multiplexed signalprocessor 16 of the decoder 17. As will be subsequently seen, each tone playble on the guitar, as well as each organ voicing control switch that is manipulatable from the guitar is assigned to a specific time slot during the time frames.

When the play of a musical tone is detected from the sampled conditions, the encoder responds during the time slot assignment of the tone detected to generate an appropriate signal that is indicative of the play. A similar signal is generated in the appropriate time slot when a voicing control switch is detected in use from the sampled conditions. In the embodiment illustrated, the output 20 of the encoder comprises a series of time multiplexed signals that are generated by a gate in response to control signals which are generated in separate sections of processor 13. Each of these sections is either associated with one of the guitar strings or with a bank of voicing control switches.

In the embodiment illustrated, the oscillator 14 serves to generate time spaced clock pulse output signals 21 which are routed to both the time slot generator 12 and time slot counter 15, as seen in FIG. 1. Generator 12 operates in dependency upon receipt of the clock pulse signals 21, and, as will be subsequently seen, serves to generate a separate control signal for each of the seven sampling and data processing sections of the encoder processor 13. Six of these sections are devoted to sampling conditions and processing electronic data that relates to the play of the musical tones on the strings, whereas the remaining section of processor 13 is devoted to sampling conditions and processing data that relates to the use of the voicing control switches. The control signals for initiating the sampling procedures in each of the sections are generally designated at 22 in FIG. 1. Each section of processor 13 also operates in dependency upon receipt of the clock pulse output signal 21 as will be subsequently evident. In addition to control signals 22, generator 12 also generates a control signal 23 during each time frame and which is routed to the time slot counter 15 and also to the tone sustain control section 18 for synchronizing the operation of the decoder and sustain control section with that of the encoder operation.

The time multiplexed signal processor 16 of the decoder 17 utilized in the illustrated embodiment has a plurality of 8-bit latches and the encoder output 20 is routed, as seen in FIG. 1, through gate 19 to each of the latches of section 16. Each bit section of each latch is either assigned to a spare time slot in the time frame or is assigned to a time slot associated with one of the control switches or musical tones playable on the guitar. Those latch sections assigned to the guitar tones and control switches 26a have outputs connected to the appropriate electronic switches of the organ for routing the harmonically related tone signals from the organ tones producer network 26 to the audio amplifier 27 of the organ. f

The time multiplexed signals generated during each time frame are also routed to the tone sustain control section 18 of the control system, as seen in FIG. 1. This section is controllable by the guitar player to store electronic data reflecting the multiplexed signals received during a time frame and thereafter, during succeeding time frames, to generate pulse signals 28 during the time slot assignments of the guitar tones and switches assigned to the time slot occurrences of the multiplexed signals received during the preceding time frame. These signals 28, during the operation of the sustain control section, are combined in gate 19 with the signals in the encoder output 20 to provide a composite output 29 in the form of a series of time multiplexed signals that are fed to the decoder.

Reference is now made to FIG. 2 and wherein the time slot generator 12 is seen as including a decade counter 30, a decade counter 31 and a sixteen stage decoder 32 that operates under the control of the counters and 31. Counter 30 has a binary output and is wired to serve as a divide by five scaler. The clock pulse input terminal (CP) of counter 30 is connected by lead 33 to the output terminal of oscillator 14. The clock pulse signals from the oscillator are subjected to inversions in inverters 34, 35, 36 and 37 which are series connected in the lead for providing drive power and are fed as indicated in FIG. 2 to counter 30. The third stage binary output (Q of counter 30 is tapped by lead 38 and delivered via inverter 39 to the clock pulse input terminal (CP) of counter 31. The output of inverter 39 is in turn tapped by lead 40 and is delivered to the parallel enable input terminal (E) as the enabling signal to the decoder stage which is then being addressed by the four stage output signals of counter 31.

Decade counter 31 is wired to count under the control of the third stage pulse output of counter 30 to 15 and to thereafter reset during the sixteenth count. The signals from the binary output terminals (Q (Q (Q and (Q of the four flip-flop stages of counter 31 are delivered to the input terminals (A (A (A and (A.,) of the decoder address circuit. The arrangement is such that the stages of decoder 32 are addressed successively for periods corresponding to the time duration of five pulses from oscillator 14 and during the fifth pulse output from the third stage of counter 30 are enabled to provide the signals 22 that control the cyclic operation of the condition sampling and data processing sections of processor 13 and also to provide the sync signal 23 for synchronizing the decoder section with the encoding section of the control system. Thus the outputs of the first six stages of decoder 32 are tapped by leads 41, 42, 43, 44, 45 and 46 and delivered as the control signals for the string condition sampling and data processing sections 51, 52, 53, 54, 55 and 56 (FIG. 3) while the eleventh stage output of the decoder is tapped by lead 47 and delivered to the switch condition sampling and data processing section 57 of processor 13. The output of the sixteenth stage of decoder 32 is tapped by lead 48 and delivered via inverters 58, 59, 60 and 61 as the control signal to the a input of a gate component 138 of the time slot counter 15. The arrangement and operation of the time slot generator 12 is such as to provide discrete time slots during the operating cycle of the encoder and decoder for reasons which will be .subsequently apparent.

Reference is now made to FIG. 3 and wherein each of the string condition sampling and data processing sections 51 through 56 inclusive is shown as associated with a respective one of the guitar strings 62 through 67 inclusive. Sections 51 through 56 are connected in the data processing circuit of encoder 11 in parallel with each other and in parallel with the switch condition sampling and data processing section 57. The outputs generated by these sections are delivered as control signals to gate and serve to control the generation of the multiplexed signals by gate 85 during the appropriate time slots.

Each guitar string in the embodiment illustrated has a bank of sensors that provide a means for sensing conditions that are developed by the play of the musical tone selections on the string. These sensing banks are designated at 71 through 76 inclusive and each bank of sensors is monitored and the sensed condition sampled by a shift register component of the data processing section associated with the string as will be'more apparent subsequently.

The string condition sensing arrangement used in the illustrated embodiment is founded, insofar as it relates to keyed string tones that are playable on the strings, on a switching action that transpires when the guitar string is pressed against the keyboard at the selected keying position and into string keying contact with the fret associated with the tone playable on the string at the selected position. Thus, the conventional six string guitar has 22 positions at which the strings are keyed and each position is provided with a fret which underlies the strings. In the illustrated embodiment, the fret at each string keying position on the keyboard is segmented to provide a segment which underlies each of the strings and each segment ismade of electrically conductive material that is electrically-isolated from the other fret segments that are mounted on the keyboard. The arrangement provides a plurality of fret segmentswhich underlie each guitar string and which are spaced apart on the keyboard and located at the respective positions for keying the string against the keyboard.

As explained in theaforementioned copending patent application, one of the difficulties that has confronted efforts to develop keyed string tone switching arrangements founded on electrical contact between a string and the fret segment is the fact that the string may momentarily contact one or more frets in the process of being keyed at a selected position. Furthermore, at the selected position the string simultaneously contacts not only the fret segment which keys the string at the selected keyboard position but it also contacts the fret segment at the adjacent keyboard position that is associated with the next lower pitched keyed string tone that is playable on the guitar string. As will be subsequently seen the string data processing section in accord with the illustrated embodiment is designed to monitor the sensor bank associated with the string and to periodically on a timed basis sample the sensed conditions and detect those conditions which are indicative of a tone selection being played on the string.

Insofar as the keyed string tones are concerned, their play is detected by storing an electronic information bit for each fret in contact with the string at the time the sample is taken. These information bits are then screened during the operating cycle of the section to detect the stored information bits which represent simultaneous string contact with adjacent frets at the time of the sample. When such simultaneous contact is detected, the section operates to generate a control signal during the time slot assignment of the keyed string tone being played on the string. A serial shiftregister is used to sample and store the information bits pertaining to the sensed string contacts with the frets and the register is controlled to generate an output in response to each fret that is contacted and to do this in a time slot that has a predetermined time offset from the time slot assignment of the musical tone selection which would be playable on the string by keying the string into contact with the fret. To compensate for the lack of string contact with a fret segment when the open tone is being played on the string, a metal or other electrical ly conductive touch plate is mounted under each string at the first position for keying the string so that the electronic data indicative of the play of the keyed string tone associated with the first keyboard position on the guitar is based on string contact with the touch plate as well as with the fret segment against which the string is keyed at the first keyboard position of the guitar.

Insofar as the string condition sensing arrangement used in the illustrated embodiment relates to sensing the open string tones that are playable on the guitar strings, it involves the use of any suitable sensor which can detect the open string tone movement either through direct physical contact with the string or indirectly as by sensing sound waves or magnetic field changes attributable to open string tone movement of the string. In the instant case' a conventional magnetic pickup principle is used to detect open tone string movement that interrupts a magnetic field. The output of the pickup is amplified and suitably modified to provide an 0 condition when the open string tone is being detected and otherwise to provide a l condition when such movement is absent for reasons which will be evident subsequently.

Reference will be made herein to O and l levels or conditions, and it should be understood as having reference to relative voltage levels where the 0" level or condition is lower than the 1 level or condition.

As seen in FIG. 3, each of the guitar strings 62 through 67 inclusive is grounded to an 0 condition and is strung between a conventional bridge and guitar nut that are respectively designated at 68 and 69.

The string condition sampling and data processing sections 51 and 52 for the number one and number two strings of the guitar are identical and the string condition sampling and data processing sections 53, 54, 55 and 56 for strings 64 through 67 inclusive are also identical to each other and differ in makeup from sections 51 and 52 only in that they lack a flip-flop-that is used to delay the output signal from the sections one time slot for reasons of the tone offset between strings two and three. Thus on the chromatic scale strings one and two are offset by five tones. String numbers two and three on the other hand are offset by four tones while the offset between strings three and four, four and five, and five and six is five tones on the chromatic scale.

Since the strings data processing sections of processor 13 are controlled by pulse control signals from decoder 32 that are offset a matter of five time slots in each case, the additional flip-flop in sections 51 and 52 as will be subsequently seen serves to compensate forthe four tone offset between strings two and three in the embodiment illustrated. I

The composition and operation of the string condition sampling and data processing sections 51 and 52 that are associated with strings 62 and 63 will be evident from a consideration of the components of section 51. Section 51 includes a 24-bit parallel load shift register in which electronic data pertaining to the sensed string conditions are loaded during each time frame, and a pair of flip-flops 81 and 82 which together with a gate 83 serve to screen the electronic data stored during the timing cycle to detect those sensed conditions which are indicative of a tone selection being played'on the string. When such is detected gate 83 provides an appropriate output signal. This signal is then delayed for one time slot in flip-flop 84 and fed as a control signal during the occurrence of the time slot assignment of the detected tone to a seven input gate 85 which in turn responds to receipt of the signal to generate a time multiplexed signal component in the output of the enand fed to a bus 87 that serves sections 51 through 57.

This signal is in turn tapped by lead 88 and fed to the clock pulse input of flip-flop 84 and by leads 89, 90 and 91 is also tapped and fed to the clock pulse inputs of register 80, and flip-flops 81 and 82. Section 51 while operating in dependency upon receipt of the clock pulse signal generated by the oscillator is controlled in its cyclic operation by the first stage output signal that is generated in decoder 32. Thus the pulse output in the fourth time slot of the cycle is delivered by lead 41 as a control signal to the direct set input (DS) for flip-flop 82 and is tapped by leads 92 and 93 and delivered to the load input (L) of register 80 and to the reset input (R) of flip-flop 81.

Each flip-flop of the 24-bit register 80 has a direct load input, and the input of the first stage flip-flop of the register is connected by lead 94 to receive the output of the open tone sensor 95 of the sensor bank 71. The input of the second stage of the register is connected by lead 96 to the touch plate 97 at the first string keying position on the keyboard, the leads 94 and 96 are electrically interconnected through a diode 98. The direct load inputs for stages three through 24 inclusive are electrically connected by leads generally designated at 99 to the respective fret segments that underlie the number one string at the first through twenty-second string keying positions respectively.

In the embodiment illustrated the compliment or 6 output of the twenty-fourth stage of register 80 is delivered by lead 100 to the data input terminal of flip-flop 81. This signal is also tapped by lead 101 and delivered to the a input terminal of the three input and gate 83. The Q output of flip-flop 81 is delivered by lead 102 to the b input of gate 83 and the Q output of flip-flop 82 is delivered by lead 103 to the input terminal of gate 83. The output (1" of gate 83 is delivered by lead 104 to the data input terminal of flip-flop 84 and by lead 105 this output signal is tapped and delivered to the data input of flip-flop 82. The 0111 output of flip-flop 84 is delivered by lead 106 to the 11" input terminal of the seven position or" gate 85.

The string condition sampling and data processor sections 52 for the number two string 63 is identical in composition and operation to that of processor section 51 except that the section operates under the control of the pulse signal from the second stage of decoder 32 and which is fed to the section 52 by lead 42. The sensor banks 72 is also identical to that used with the other strings and the output from section 52 is fed by lead 107 to the b input terminal of gate 85.

The composition of the data processor sections 53, 54, 55 and 56 that are associated with strings 64, 65,

66 and 67 is illustrated by reference to section 53 and wherein it will be seen that each of these sections has a 24-bit register 80a, and a pair of flip-flops 81a and 82a which together with gate 83a are wired to perform the data screening and detecting function for the electronic data stored in the 24-bit serial shift register 80a in a manner similar to that performed by the corresponding components of section 51. Sections 53, 54, 55 and 56 operate under the control of the-time spaced signals delivered to the sections by leads 43, 44, 45 and 46 respectively and the outputs of the sections are delivered as control signals by leads 108, 109, 110 and 111 to the c, d", e and 1" inputs of gate 85 as shown in FIG. 3.

The switch condition processing section 57 also comprises a 24-bit serial shift register 112 which like the shift registers of the string data processing sections operates in dependency upon receipt of a time spaced pulse output signal from the oscillator. The operation of this section is initiated during each timing cycle by the pulse output of the eleventh stage of decoder 32 and which by lead 47 is delivered to the load input of' register 112. As will be subsequently seen, a 1"condition is maintained at the direct load input terminals of the 24 stages of register 112 as with the other shift registers associated with the other sections. In this case the direct load inputs 22 and 23 are connected to ground' by leads 113 and 114 through switches 115 and 116. These switches 115 and 116 are associated with separate voicing control circuits in the electronic organ and during the cyclic operation of the section will cause the delivery of a control signal to the g input terminal of gate 85 as by lead 117 during the appropriate time slot assignments for the switches detected in use.

As shown in Table I each tone playable on the guitar strings is assigned to a specific time slot with the highest note playable on the guitarbeing the D tone played by keying the number one string at the twenty-second position being assigned to the seventh time slot whereas the lowest tone, being the open string tone playable on the number six string, is assigned to the fifty-third time slot. This reflects an orderly assignment of the musical tones of progressively changing pitch to successively occurring time slots during a time frame. Each voicing control switch is also assigned to a specific time slot as seen in Table I. Table I also shows the input assignments for the 24-bit shift registers associated with the string and switch data processing sections.

The operation of the number one string condition sampling and data processing section 51 and the operation of the sensor bank 71 associated therewith is illustrated by reference to the timing diagram shown in FIG. 6 and wherein it is assumed that the number one guitar string 62 is depressed at the twentieth keyboard position 119 to play the high C note on the string. The direct load inputs of the 24 stages of register 80 are normally at a I condition, and when string 62 is thus depressed, it contacts and is keyed against fret segment 120 to establish the mode of vibration'of the string. The string also contacts the fret segment 121 that underlies the string at the next lower number string keying position and which is associated with the next lower pitch tone playable on the string, namely the high B" tone. String 62 like the other strings of the guitar is grounded, and the contact with the fret segments 120 and 121 at the twentieth keyboard position imposes an 0 condition on the input terminals to the twenty-first and twenty-second stages of register 80. With this assumed condition existing at the commencement of the timing cycle, the timing cycle insofar as it relates to section 51 is initiated by receipt of the pulse signal 122 during the fourth time slot from the first stage of decoder 32. This control signal 122 overrides the shifting action of the clock pulse input to register 80 and loads the twenty-first and twenty-second stages of the register with an 0 condition while the other stages of the register remain at the 1 condition. The 0" conditions loaded in the twenty-first and twenty-second stages constitute electronic information bits which reflect string contacts with frets 120 and 121 at the time of the sample and remain during the fifth time slot. The control signal 122 by application to the reset input terminal (R) of flip-flop 81 establishes an 0" condition at the b input terminal of gate 83 and also serves to set flip-flop 82 to a l" condition which is imposed upon the c input of gate 83 and thereby conditions the gate. The 0 conditions in register stages 21 and during the sixth and seventh time slots, and as the condition in stage 23 shifts to stage 24 at the commencen ent of the seventh time slot the l condition of the Q output of stage 24 is imposed upon the a input terminal of gate 83 and also on the data input of flip-flop 81. The l condition at the a input of gate 83 remains during the eighth time slot by virtue of the shift of the 0 condition from the twenty-third stage to the twenty-fourth stage of the register during the eighth time slot. The l condition at the data input (D) of flip-flop 81 during the seventh time slot is loaded into the flip-flop at the commencement of the eighth time slot, and this opens gate 83 and provides an 0 pulse output 123 from the output terminal (d) of gate 83 during the eighth time slot. This pulse output during the eighth time slot is delivered to the data input (D) of flip-flop 82 and this drives the flip-flop 82 to the 0 condition at the commencement of the ninth time slot and thereby closes the gate during the remainder of the timing cycle. The pulse output 123 during the eighth time slot shifts to flip-flop 84 during the ninth time slot that has been assigned to the C note and the output Q of this flip-flop 84 is imposed upon the a input of gate 85 to generate a signal in the output of gate 85 and in the time slot assigned to the high C note or tone playable on the string. The output of gate 85 is transmitted by electrically conductive lead 125 through inverter 126 to the decoder section of the control system as will be subsequently seen.

The sensor bank 71 provides a means for monitoring the play of musical tones on the number one string and section 51 serves to cyclically detect the play of a tone selection and to thereafter generate a signal appropriately indicative of the selection and in the time slot assignment of the played section.

A consideration of the timing diagram shown in FIG. 6 will show that each information bit that is stored at the time of the sample in response to a sensed stringl contact with a fret appears as the Q output of the twenty-forth stage during a time" slot which is offset by three time slots from the time slot assigned to the musical tone obtained by keying the string into string keying contact withthe detected fret. p

Flip-flops 81 and .82 in conjunction with gate 83 serve to process electronic data stored by register 80 at the commencement of the cycle to detect the sensed conditions which indicate the play of a selection on the string. Thus at the time of the response to the control signal 122 gate 83 is primed to respond to simultaneous l condition outputs from the twenty-fourth stage of register 80 and from flip-flop 81. Such response, however, only occurs when a l condition is generated at the 6 output of the twenty-fourth'stage during each of successively occurring time slots.

When string 62 is keyed at the first keying keyboard 12 have been loaded in the second and third stages of register during thefourth time slot. the shifting action and data processing is comparable to that previously described except that the output control signal from flip-flop 84 occurs during the twentyeighth time slot assigned tothe F toneor note obtainable by keying the string at-the first keyboard position. When the open string tone is played on string 62, sensor establishes a ground or 0 condition at the input terminal of the first stage of the register, and by virtue of the diode 98, this condition is also established at thedirect load input of the second stage flip-flop of the register. Thereafter the operation of the circuit components of the string sampling and data processing section 51 is similar to that previously spelled out except that the pulse output indicative of the playing of the open string tone appears in the Q output of flip-flop 84 during the twenty-ninth time slot assigned to the tone.

Section 52 as previously indicated operates in the same manner as section 51 except that the control signal delivered by lead 42 appears in the ninth time slot to commence the cyclic operation of the section. Seetions 53. through 56 also operate in the manner of section 51 except for the control signals and the fact that the gate outputs are delivered directly to the or gate 85 without the need for the time delay associated with the use of flip-flop 84 in section 51. The operation of the switch condition sampling and data process section 57 is believed apparent from the described operation of register 80. Briefly however, when voicing control switch 116 is closed an 0 condition is imposed upon the input to the twenty-third stage of register 112. The

load input of register 112 is connected to the eleventh stage output of decoder 32 by lead 47 so that the conditions of the switches are sampled in response to receipt of the pulse output of the decoder stage during the fiftyfourth time slot. As such, the 0 condition in the twenty-third stage of register 112 shifts with each succeedingclock pulse input and appears as an output signal in lead 117 during the time slot assigned to the switch..Gate 85 as previously indicated generates a series of time multiplexed signals and wherein each signal is generated in response to a control signal received from one of the sampling and data processing sections 51 through 57.

The time slot counter 15 of decoder 17 includes a four stage binary counter that is wired to function as a divide by eight scaler. It has a'total count output (TC) that is delivered by lead 131 to the data input terminal (D) of a decade counter component 132 of thecounter 15. Counter 15 also includes a 10 stage addressable decoder 133 that operates under the control of counter 132.

The time space clock pulses from oscillator 14 are tapped at the output of inverter 34 and delivered via. inverter 134 in lead 135 to the clock pulse input terminal (CP) of binary counter 130. The total count output signal of binary counter 130 is tapped by lead 136 and delivered through inverter 137 to the b input terminal of an or" gate 138. The sync signal during the seventy-ninth time slot is delivered by lead 48 to the a input of gate 138 as seen in FIG. 2. The output of gate 138 is passed via lead 139 through inverter '140 to the parallel enable input terminal (PE) of the four stage binary counter 130 and the signal is also tapped by lead 139a and deliveredto the parallel enable input terminal (PE) of decade counter 132, so that the operation of counter is referenced tothe sync pulse delivered from the time slot generator section of the encoder 11. The output terminals (0.), (Q and (Q of the first three stages of'counter 130 are tapped by leads generally designated at 141 and are delivered to each of the address circuits of the 8-bit latches that are used in the time multiplexed signal processor 16. As will be subsequently seen, these binary outputs are used to successively address the stages of each latch.

The clock pulse output signal of oscillator 14 is tapped by lead 142 and delivered to the clock pulse input terminal (CP) of decade counter 132 and the output terminals (Q (Q (Q3) and (Q of the four stages of counter 132 are tapped by lead 143 and delivered to the address circuit input terminals (A (A (A and (A of decoder 133. Decade counter 132 also has a total count output terminal (TC) and this is connected by lead 144 for reasons which will be subsequently explained.

Decoder 133 has ten stages that are successively addressed by the binary outputs of counter 132 and the clock pulse from oscillator 14 is delivered by lead 145 to the parallel enable input circuit of the ten stage decoder 133. The operation of the time slot counter is such that each stage of decoder 133 is addressed for a period of eight clock pulses by the outputs from decade counter 132 and is enabled when being addressed by each of the clock pulses that are delivered to the decoder from oscillator 14. As such, each decoder stage has an output that comprises a train ofeight pulses during the period in which it is enabled and these pulse output signals from the IQ stages are delivered by leads 150 through 159 inclusive to the respective latches of processor 16.

The pulse signals in the encoder output from the or gate component 85 of the encoder section are inverted in inverter 126 and by lead 125 passed to the b" input terminal of the or gate 19 that serves the chord sustain section 18 of the control system 10.

The time multiplexed signal processor 16 comprises, in the embodiment illustrated, ten, 8-bit addressable latches that are designated at 160 through 169 inclusive. Each latch has a data input terminal (D) and the time multiplexed signals in the output 20 from the or gate 19 is delivered to the data input terminal (D) of each latch as seen in FIG. 4. The address circuits of each latch are connected to the output leads 141 of the binary counter 130, as also seen in FIG. 4. As the binary counter 130 counts with each clock pulse fed to it from the oscillator 14, the stages of each latch are sequentially addressed with the first stage of each latch being initially addressed simultaneously, the second stage of each latch being addressed in the next time slot and so on so that each latch is addressed once with every eight clock pulses. Each latch however, is connected to a different stage of decoder 133, and consequently each latch stage only receives an enabling pulse once during each timing cycle. The outputs of each latch are normally at an 0" level and when enabled will assume the output condition of the data input so that if the signal 29 has a I level during the time slot when the stage is enabled, then the output of the stage will assume the 1" level until such time as the 0 condition appears in the signal 29 during the assigned time slot of a subsequent time frame. The time slot and tone or switch assignments for the outputs of the latches are set forth in Table II and FIG. 7 exemplifies the operation of the processor 16 when the high C tone is being played on'one of the guitar strings. Under such circumstances the output of gate bears a pulse signal 124 during the ninth time slot and which is indicative of the play of the C note on one of the strings of the guitar at the commencement of the time frame. Signal 124 is inverted by inverter 126 and again by or gate 19 and appears as a 1 level pulse signal 124 in the data input (D) of each of the latches. During time slots 8 through 15 the number two latch 161 is fed a train of pulses 172 and the address circuits address the second stage of each of the latches during the ninth time slot so that the (Q output of the number two latch 161 is enabled by the receipt of a pulse 173 dur ing the time slot when a l level pulse signal appears in the datum input. This enables the second stage (Q output by providing a 1 level condition which controls and enables the tone producers of the electronic organ to produce an audible C tone that is harmonically related to the corresponding tone being played on the guitar.

The chord or tone sustain section 18 of control system 10 is designed to enable the guitar player to initiate the playing of a chord or tone on the guitar and to thereafter sustain the playing of the same chord or tone on the organ after the guitar player has ceased playing the tone selection or selections on the guitar.

Section 18 as seen in FIG. 5 includesan 80-bit serial shift register which has a data select input terminal (DS) and which is wired as a loop register with the output terminal (Q of the eightieth stage being connected by lead 181 to one of the data input terminals (D of the first stage of the register. The output 20 of the encoder is fed to the 12" input of gate 19 and is tapped by lead 182 and delivered via inverter 183 to the other data input terminal (D of the first stage of the register. The sustain section also has a two input and gate 184 and the output signal of register is tapped by lead 185 and delivered to the a" input of gate 184. The clock pulse input of register 180 is provided by a lead 186 that taps the output signal from in verter 134 and delivers the signal to the clock pulse input terminal (CP) of shift register 180.

The sustain section has a circuit that controls the signal fed to the register in the operation of gate 184. This circuit includes an and gate 188, a flip-flop 189 and a switch 190 which is normally opened and which may be manually controlled by the guitar player to control the operation of the sustain section. The switch is preferably a foot switch.

The a input ofand gate 188 is connected by lead 144 to the total count output of decade counter 132 of section 15. The b input of gate 188 is connected by a lead 187 that taps the pulse output signal from inverter 34. This arrangement provides a l level pulse during the seventy-ninth time slot of each timing cycle and which opens the gate 188 and by lead 191 applies a pulse at the clock pulse input (C?) of flip-flop 189. The data input terminal (D) of flip-flop 189 is connected by lead 192 through inverter 193 and resistor 194 to a positive potential, and lead 192 is tapped by a lead 195 that through switch 190 is connected to ground. The Q output of flip-flop 189 as seen in the drawings, is fed by lead 196 to the b input terminal of gate 184 and this lead is tapped in the embodiment via lead 197 that delivers the 0" output of flip-flop 189 to the data select terminal (D8) of register 180.

When switch 190 is opened, an condition is applied to the data input of flip-flop 189 and with each clock pulse that occurs during the seventy-ninth time slot, the 0 condition is stored in the flip-flop 189 for the period of the next timing cycle. As a result, an 0 condition is applied to gate 184 and which maintains the gate in a closed condition for the cycle. Similarly this applies an 0" condition to the data select terminal (DS) of register 180 and this selects the signal delivered to the (DO) input terminal as the data fed to the register 180. Hence the time multiplexed signals being delivered to gate 19 are applied after inversion in inverter 183 to the first stage input of the register and the electronic data stored in the register during the previous timing cycle is blocked from passage to the processor by the closed condition of gate 184.v

When the foot switch 190 is closed however, the input to inverter 193 is grounded and a 1 level condition is established at the data input terminal (D) of flipflop 189. This 1 level condition is then stored in the flip-flop 189 by the next clock pulse which in time corresponds to the sync pulse, and a I level condition is established at the data select terminal (D5) of register 180 as well as at the b" input terminal of gate 184. This primes gate 184 and causes selection of the (D input terminal of the register so that the electronic information bits stored in the register during the previous time frame are caused to loop back through the register and by virtue of the lead tap 185 are delivered to gate 184. Gate 184 accordingly is enabled during each time slot where the output of the register 180 has an -l level pulse and this of course is passed via lead 198 to the "a input of or gate 19 and where it enables the gate to generate a signal during the time slot. The operation of the sustain section is exemplified by reference to FIG. 8 and wherein it will be seen that flip-flop 189 receives but one pulse 200 during each time frame.

In Example One it is assumed that the foot switch is initially opened during the fortieth time slot of cycle (1) and thereafter closed during the fortieth time slot of cycle (N-l) while the high C tone signal is entered into the encoder during each of the cycles (2) through (N-2). Under such circumstances the 1 level pulse 201 in the output 20 of the encoder during cycle (2) appears as a I level output pulse signal 202 that is blocked from passage from the sustain section by the 0" level condition at the b" input of gate 184.

In Example Two" it is assumed that the foot switch is closed during the fortieth time slot of cycle (1) and thereafter opened during the fortieth time slot of cycle (N-l) while the high C note signal is entered into the encoder during cycles l-N) through (2) .inclusive. Under such circumstances the foot switch imposes a 1" level condition at the d input of flip-flop 189 while the switch is closed and upon receipt of the clock pulse output signal 200 from gate 188 the Q output of flip-flop 189 imposes a 1 level priming condition on the b" input of gate 184 and, through the data select terminal selects the data at the (D input as the data input to the first stage of register 180. As such, the pulse signal 203 during cycle (2) is blocked from entry into the register 180 by the condition at the data select input terminal but the signal that was entered into the register during the ninth time slot of cycle (1) appears as a pulse 204 in the corresponding time slot of cycle (2). By virtue of the primed condition of gate 184, this pulse 204 appears as an inverted pulse 205 in the output of gate 184 and enables gate 19 to thereafter, during each cycle while the gate is opened, to provide a pulse signal indicative of the playing of the high C tone on the guitar during the time slot associated with this note. This, of course, results in a sustained playing of the high C" note on the organ until such time as the foot switch is again opened and the clock pulse during the next seventy-ninth time slot of a timing cycle causes the gate to close. I

In the embodiment illustrated in FIGS 1 through 8 the decoder and encoder sections of the control system are shown as connected by three electrically conductive leads or wires, one for transmitting the sync signal, a second wire'for transmitting the time multiplexed signals, and a third wire for transmitting the oscillator output signal. This type arrangement minimizes the probability of electrical failures due to the use of a large number of wires and avoids the need for a bulky cable-type interconnection between the two musical instruments. If one wants to avoid the use of all wire connections betweeninstruments playable in duet fashion, the signals can be transmitted between the instruments by radio signals and FIG. 9 illustrates a system which may be employed for playing an electronic organ in duet fashion with an accordian.

In this instance the accordian which is generally depicted at 210 is assumed to have 41 treble key switches,

12 bass key switches, 12 chord key switches and to be further equipped with 12 voicing control switches. The

system for controlling the electronic organ 211 is desig nated at 212 and is founded on the production of a series of time multiplexed output signals during successive time frames that have time slots. Sixty-tive 'of these time slots are assigned to the treble, bass and chord key switches associated with the tones and chords playable on the accordian and twelve time slots are assigned to the voicing control switches associated with the voicing circuits of the electronic organ. One time slot is assigned for a sync signal and the other two time slots are spares.

The control system includes an oscillator 213 and'encoder 214 that has a divide by eighty scaler 215 and an 80-bit parallel load serial shift register 216. It-also includes a pulse width enccoder 217 and a radio transmitten 218. The oscillator 213, encoder 214, pulse width encoder 217 and transmitter 218 are associated with and mounted on the accordian 210. The control system also includes a radio receiver 220, a pulse width decoder 221, a divide by 80 counter 222 and an 80-bit latch 223. The counter 222 and latch 223 serve as a decoder 224 for the series of time multiplexed output signals produced in the encoder section of the control system.

In the operation of the system oscillator 213 serves to generate a time spaced clock pulse output signal '226 that is delivered to the scaler 215 to provide a sync signal 227 that divides the clock pulse signal into a series 17 switches 230 is mechanically coupled to one of the treble, bass or chord keying switches and is closed by operation of the keying switch while switches 231 are ,manually manipulatable to a closed position to enable the voicing circuits associated with them. As seen in FIG. 9, the pole pieces of switches 230 and 231 are connected to ground 232 while the switch contacts are connected to the input terminals of the respective stages of register 216 as by leads 233.

In the normal operation of the accordian 210 one or more of the switches 230 is closed as a tone selection is being played on the aceordian and the status of the switches is sampled at the commencement of each cycle in response to a control signal derived by a wire tape 234 in the sync output circuit of sealer 215. When the sync signal is received by register 216 the stages of the register are loaded and an condition is established in those flip-flop stages which are connected to a closed switch component. Thereafter under the influence of the clock pulse signal, electronic data or information bit are shifted from one stage to the next with each clock pulse signal and an output 235 is produced each time frame with time multiplexed signals being generated in those time slots assigned to the respective switches that had a closed condition at the time of the register response. In the embodiment illustrated, the

- time multiplexed signals in the output 235, the sync pulse 227 and the clock pulse signals 228 are encoded in a pulse width encoder 217 and a composite signal 236 is delivered to radio transmitter 218 which via antenna 237 transmits the encoded signals as modulated on a radio wave to the antenna 238 associated with the organ. The radio signal is then delivered to the radio receiver 220 and the composite pulse width signal after demodulation from the carrier and is transmitted by lead 239 to a pulse width decoder 221 which separates the composite signal into its component parts. The sync signal is delivered by lead 240 to a divide by counter while the time multiplexed signals are delivered by lead 241 to the data input of the 80-bit latch. The clock pulse signal component is delivered by lead 242 to the parallel enable input (E) of the 80-bit latch 223 and is tapped by lead 243 and also delivered to counter 222. Counter 222 generates a binary output 244 that is fed to the address circuit inputs (A) of the 80-bit latch 223. Each stage of latch 223 has an output that is connected by a lead to the appropriate tone or voicing control switch of the organ 211 tone and voicing switches 211a so that when the output is energized the switch closes to deliver the harmonically related tone from the tone signal generator network 245 to the audio amplifier 246 of the organ when the switch is one of the tone control switches. When the stage of the latch is associated with one of the voicing control circuits of course the output of the network 245 is modified by the special effects circuitry associated with the tones being delivered to the amplifier 246.

In the normal operation of the latch the address outputs 244 of counter 222 serve to sequentially address the stages of the latch 223 and the pulse in the clock pulse signal serves to enable the address stage which like the latch stages in the prior embodiment will assume an output condition corresponding to the signal being delivered to the latch at the time the stage is enabled and will retain the condition so long as the data component appears in the time slot associated with the latch stage during subsequent cycles.

While only certain preferred embodiments of this in- Table l T /S Guitar Tone and Voicing Switch T/S Assignments ()0 (SP) (ll (SP) ()2 (SP) 03 (SP) 04 (SP) ()5 (SP) 06 (SP) ()7 D*# 24 08 C 23 ()9 C 22 I0 B 21 l l A 20 12 A l9 l3 G l8 14 G l7 IS F l6 16 F l5 17 E 'l4 18 D l3 I9 D 12 20 C l l 21 C It) 22 B 9 23 A 8 24 A# 7 25 (i 6 26 (i# 5 (Storage Register Stage Input Assignments) No. 1 String Register Stage No. 2 String Register Stage No. 3 String Register Stage N0. 4 String Register Stage No. 5 String Register Stage No. 6 String Register Stage Switch Register Stage 23 22 21 20 I) 24 I8 23 I7 22 I6 21 I5 20 Tablc I Coggnued 27 F 4 9 l3 18 23 28 F 3 8 l2 I7 22 29 F,# 2-] 7 ll )6 2l 30 D 6 l I 3] l)# 5 9 l4 I9 24 32 C 4 8 l3 I8 23 33 C 3 7 I I7 22 34 B# 2-] 6 II If: 21 35 A 5 l0 I5 20 36 4 9 l4 I9 37 y 3 8 l3 I8 38 G 2-1 7 1 I7 39 F 6 I) I6 40 F 5 l0 )5 4| f 4 9 )4 D 3 8 I3 43 2-1 7 I2 44 6 ll 45 C 5 IO 46 B 4 9 47 A 3 8 48 A 2-l 7 49 G 6 50 G 5 5l F 4 52 F 3 53 E** 2-l 54 (SP) I 55 (SP) 56 (SW) 21 57 (SW) 22 58 (SP) 59 (SP) 60 (SP) 6] (SP) 62 (SP) 63 (SP) 64 (SP) 65 (SP) 66 (SP) 67 (SP) 68 (SP) (:9 (SP) 7() (SP) 7l (SP) 72 (SP) 73 (SP) 74 (SP) 75 (SP) 76 (SP) 77 (SP) 78 (SP) 79 (SY) (SP) =Spnrc (sw) Switch (SY)= Sy nc Highest Tone "Lowest Tone Table II (SF) (SP) V(SP) (SP) (SP) (Latch Output Tone and Switch Assignments) No. I Latch N0. 2 Latch N0. 3 Latch N0. 4 Latch N0. 5 Latch No. 6 Latch No. 7 Latch No. 8 Latch No. 9 Latch N0. l0 Latch Table I I Continued 14 (i IS F# O1 16 F 0. 17 E 0- IX I)# 0.: w o O 20 c 0:, 2| c 0.,- 22 u 0 23 A# o: 24 A 0 25 0; 2a (a O. 27 0: 2x F 05 29 l5 0 30 0* Q: 31 I) Q 32 c Q- 33 C 02 34 l O 55 7: 0: as A O. 37 G# Q; as o 0 39 F# O: 40 F 0. 4| 0 42 I 0.: 43 D O 44 C# 45 C on 46 B Q 47 A# 01 4s A O 49 G# O; 50 o 0. 5| F# 0: 52 F 0.5 53 E Q 54 (SP) 55 (SP) 56 (SW) Q1 57 (SW) 0, 58 (SP) 5) (sP) m) (SP) ()1 (sP) 62 (SP) ()3 P) ()4 (SP) ()5 (SP) (10 (SP) (17 (SP) 68 (SP) 9 (SP) 70 (SP) 71 (SP) 72 (SP) 73 (SP) 74 (SP) 75 (SP 76 (SP) 77 (SP) 78 (SP) 79 (SY) (SP) Spare (SW) =Switch (SY) Sync What is claimed as new and what is desired to secure by Letters Patent of'the United States is: g

1. in a combination comprising a guitar having strings with musical tones that are manually and selectably' playable thereon, a second musical instrument having means for producing audible tones which are harmonically related to said musical tones, and a system for controlling the operation of the tones producing means in accord with the selected play of said musical tones on said Strings, the improved control system comprising encoding means for detecting the play of said musical tones on said strings during each of successively occurring time frames and for generating a series of time multiplexed signals during each of said time frames, each of said time frames having a plurality of time slots, each of said musical tones being assigned to a respective one of said time slots, and each of said signals being generated in response to the detected play of a respective one of said musical tones on a string of the guitar and during the occurrence of the time slot assignment of said one tone; decoding means for decoding the time multiplexed signals and controlling the audible tones producing means to produce audible tones harmonically related to the musical tones assigned to the time slot occurrences of said time multiplexed signals, means for transmitting said time multiplexed signals 23, from said encoding means to said decoding means, and manually controllable means for sustaining the production of audible tones during subsequent time frames which are harmonically related to the musical tones assigned to the time slot occurrences of the multiplexed signals generated during a time frame preceding said subsequent time frames.

2. The improved control system in accord with'claim l where the sustaining means comprises storage means connected to receive the time multiplexed signals generated during said preceding time frame and manually controllable to thereafter generate an output signal during said subsequent time frames and during each occurrence of the time slot assignments of the musical tones assigned to the time slot occurrences of the multiplexed signals received by the storage means during said preceding time frame, and where said transmitting means comprises means operating during each of the subsequent time frames to combine the time multiplexed and output signals generated during the time frame into a series of time multiplexed signals that are transmitted to said decoding means.

3. In a combination which comprises a guitar having strings with musical tones that are manually and selectably playable thereon, a second musical instrument having means for producing audible tones which are harmonically related to said musical tones, and a system for controlling the operation of the audible tones producing means in accord with the selected play of said musical tones on said strings, the improved control system comprising encoding means for detecting the play of said musical tones on said strings during each of successively occurring time frames and for generating a series of time multiplexed signals during each of said time frames, each of said time frames having a plurality of time slots, each of said musical tones being assigned to a respective one of said time slots and in an order reflecting as assignment of tones of progressively changing pitch to successively occurring time slots, and each of said multiplexed signals being generated in response to the detected play of a respective one of said musical tones and during the occurrence of the time slot assignment of said one tone, decoding means fordecoding the time multiplexed signals and controlling the audible tones producing means to produce audible tones harmonically related to the musical tones as signed to the time slot occurrences of said time multiplexed signals, and means for transmitting said time multiplexed signals from said encoding means to said decoding means, said encoding means comprising means for generating a first controlsignal during each time frame, a section for detecting the selected play on one'of said strings of the musical tone selections that are playable thereon, and means for generating said multiplexed signals and controlled by receipt of a second control signal to generate a multiplexed signal during the occurrence of the time slot assignment of a musical tone selection detected by the section as being played on said one string, said guitar having frets which are spaced apart and underlie said strings, said one string having keyed string tones which are playable thereon, each of said keyed string tones being playable on said one string by keying'said one string into string keying contact with a respective one of said frets, said section having storage means operating in response to receipt of said first control signal to detect each fret in contact with said one string at the time of such response and to generate an output in response to the detected contact with the fretand in a time slot having a 3 comprising manually controllable means for sustaining the production of audible tones, during subsequent time'frames, which are harmonically related to the musical tones assigned to the time slot occurrences of the multiplexed signals generated during a time frame preceding said subsequent time frames.

5. The improved control system in accord with claim 4 where the sustaining means comprises second storage means connected to receive the time multiplexed signals generated during said preceding time frame and manually controllable to thereafter generate an output signal during said subsequent time frames and during each occurrence of the time slot assignments of the musical tones assigned to the time slot occurrences of the multiplexed signals received by the second storage means during said preceding time frame, and where said transmitting means comprises means operating during each of the subsequent'time frames to combine the time multiplexed and output signals generated during the time frame into a series of time multiplexed signals that are transmitted to said decoding means. 

1. In a combination comprising a guitar having strings with musical tones that are manually and selectably playable thereon, a second musical instrument having means for producing audible tones which are harmonically related to said musical tones, and a system for controlling the operation of the tones producing means in accord with the selected play of said musical tones on said strings, the improved control system comprising encoding means for detecting the play of said musical tones on said strings during each of successively occurring time frames and for generating a series of time multiplexed signals during each of said time frames, each of said time frames having a plurality of time slots, each of said musical tones being assigned to a respective one of said time slots, and each of said signals being generated in response to the detected play of a respective one of said musical tones on a string of the guitar and during the occurrence of the time slot assignment of said one tone; decoding means for decoding the time multiplexed signals and controlling the audible tones producing means to produce audible tones harmonically related to the musical tones assigned to the time slot occurrences of said time multiplexed signals, means for transmitting said time multiplexed signals from said encoding means to said decoding means, and manually controllable means for sustaining the production of audible tones during subsequent time frames which are harmonically related to the musical tones assigned to the time slot occurrences of the multiplexed signals generated during a time frame preceding said subsequent time frames.
 2. The improved control system in accord with claim 1 where the sustaining means comprises storage means connected to receive the time multiplexed signals generated during said preceding time frame and manually controllable to thereafter generate an output signal during said subsequent time frames and during each occurrence of the time slot assignments of the musical tones assigned to the time slot occurrences of the multiplexed signals received by the storage means during said preceding time frame, and where said transmitting means comprises means operating during each of the subsequent time frames to combine the time multiplexed and output signals generated during the time frame into a series of time multiplexed signals that are transmitted to said decoding means.
 3. In a combination which comprises a guitar having strings with musical tones that are manually and selectably playable thereon, a second musical instrument having means for producing audible tones which are harmonicalLy related to said musical tones, and a system for controlling the operation of the audible tones producing means in accord with the selected play of said musical tones on said strings, the improved control system comprising encoding means for detecting the play of said musical tones on said strings during each of successively occurring time frames and for generating a series of time multiplexed signals during each of said time frames, each of said time frames having a plurality of time slots, each of said musical tones being assigned to a respective one of said time slots and in an order reflecting as assignment of tones of progressively changing pitch to successively occurring time slots, and each of said multiplexed signals being generated in response to the detected play of a respective one of said musical tones and during the occurrence of the time slot assignment of said one tone, decoding means for decoding the time multiplexed signals and controlling the audible tones producing means to produce audible tones harmonically related to the musical tones assigned to the time slot occurrences of said time multiplexed signals, and means for transmitting said time multiplexed signals from said encoding means to said decoding means, said encoding means comprising means for generating a first control signal during each time frame, a section for detecting the selected play on one of said strings of the musical tone selections that are playable thereon, and means for generating said multiplexed signals and controlled by receipt of a second control signal to generate a multiplexed signal during the occurrence of the time slot assignment of a musical tone selection detected by the section as being played on said one string, said guitar having frets which are spaced apart and underlie said strings, said one string having keyed string tones which are playable thereon, each of said keyed string tones being playable on said one string by keying said one string into string keying contact with a respective one of said frets, said section having storage means operating in response to receipt of said first control signal to detect each fret in contact with said one string at the time of such response and to generate an output in response to the detected contact with the fret and in a time slot having a predetermined time offset from the time slot assignment of the musical tone selection playable by string keying contact with the fret, said one string being arranged when keyed into contact with said one fret to also contact another fret which is adjacent said one fret, and said section having means operating in dependency upon receipt of an output generated by the storage means during each of the successively occuring time slots for generating said second control signal.
 4. The improved control system in accord with claim 3 comprising manually controllable means for sustaining the production of audible tones, during subsequent time frames, which are harmonically related to the musical tones assigned to the time slot occurrences of the multiplexed signals generated during a time frame preceding said subsequent time frames.
 5. The improved control system in accord with claim 4 where the sustaining means comprises second storage means connected to receive the time multiplexed signals generated during said preceding time frame and manually controllable to thereafter generate an output signal during said subsequent time frames and during each occurrence of the time slot assignments of the musical tones assigned to the time slot occurrences of the multiplexed signals received by the second storage means during said preceding time frame, and where said transmitting means comprises means operating during each of the subsequent time frames to combine the time multiplexed and output signals generated during the time frame into a series of time multiplexed signals that are transmitted to said decoding means. 